Carburetor



July 9, 1935. M. MALLORY 2,007,337

CARBURETOR Filed Dec. 12, 1953 3 Sheets-Sheet 1 y 9, 1935. M. MALLORY 2,007,337

CARBURETOR Filed Dec. 12, 1933 Sheets-Sheet 2 T mlil Jul 9,1935. M. MALLORY 2,007,337

' CARBURETOR Filed Dec. 12, 1953 3 Sheets- Sheet 3 Patented July 9, 1935.

UNITED STATES CARBURETOR Marlon Mallory, Detroit, Mich assignor to The Mallory Research Company, Toledo, Ohio, a corporation of Delaware Application December 12, 1933, Serial No. 702,051

. 9 Claims. (01. 261-61) This invention relates to an improvement in carburetors, having for its object primarily to provide a variable venturi controlled bythe vacuum between the engine and the throttle and the 5 velocity of air passing through the carburetor.

In the present embodiment of the invention, the venturi has fuelinlet ports directed toward the center of the venturi, within which is a valve. Control of this valve depends upon two factors,

[ namely, the degree of vacuum in the intake passageway and the velocity of the airpassing therethrough. Provision is also made for shutting off the vacuum control, whenever the engine isidling or operating at a comparatively low speed with high vacuum.

The relation of the valve to the fuel intake, the manner in which the valve is controlled and the advantages resulting therefrom will be more fully explained in connection with the accompany- 50 ing drawings, in which,-

' Figure 1 is a longitudinal sectional view of a carburetor constructed according to the invention.

Figure 2 is a plan view of the carburetor. t5 Figure 3 is an elevation looking from the left of Figure 1. I

Figure 4 is an elevation lookingfrom the right of Figure 1.

Figure 5 is a sectional detail of the venturi taken on the line 55 of Figure 1.

Figure-6 is a detail sectional 'view taken on the line 3-45 of Figure 1. g

' Figure l is a central vertical section showing a modified form of the auxiliary air valve.

Figure 8 is a section through the air valve shown in Figure '7.

Figure 9 is a plan view of the valve seat shown in Figure 7.

Figure 10 is a diagrammatic illustration of the low speed fuel supply and its adjustment.

As illustrated-in the drawings, the invention is associated with a carburetor which comprises a lower casting Ill formed with a fuel chamber l I and an air chamber I2, and an upper casting l3 formed with a passageway 14 leading to the intake manifold. Admission of air to'the chamber I2 is controlled by a choke valve l5 and a throttle valve 16 is mounted within the passageway I4. I The two castings Ill and I3 are secured together by screws l'l or similarmeans and are formed with opposed annular shoulders l8 and I9 between which is secured a member 2| forming a venturi 22, through which air is drawn from the chamber l2 past the fuel ports 28 into the passageway ll.

When the engine is operating, the liquid fuel passes from the chamber ll through a port 23,

"which is regulated by a needle valve 24, into a passageway which is provided with an air bleed 25 and thence through a port 26 into-an 5 29 extending diametrically across the passageway 14 below the throttle valve and in the same plane as the throttle valve axis. Extending downwardly from the web 29 is a hollow stem 30 constituting a bearing member on which the auxiliary air valve 3| is reciprocably mounted. A spring 32 within the stem 30 urges the valve 3| toward its closed position, shown in dotted lines in Figure 1, but under'certain predetermined operating condi-' tions, the valve is adapted to be opened by suction from the intake manifold through the passageway 33, in opposition to the spring 32. The closing movement of the valve is positively limited by the engagement of its nose 34 with a vertically adjustable stud 35 which is secured in the bottom of the casting Hi. When the valve drops to a nearly closed position, the velocity of the air passing through the venturi is increased, drawing more fuel through the ports 28 and enriching the mixture.

It is desirable to out 01f the valve 3| from the influence of suction from the manifold when the throttle is closed or nearly closed. In the present construction, communication between the 35 passageway 33 and the intake chamber I4 is through a groove 37 around the valve stem 38 and through a port 39. The inlet from the pas- .sageway 33 to the groove 31 is closed when the throttle is not open'more than one eighth of its capacity.

When the engine is idling, with the throttle closed, fuel is supplied tothe intake in any suitable manner. As shown in Figures 1 and 3, there 4 is a by-pass42, 43 for this purpose, leading from a branch 25' of the fuel channel 25 into the center of the intake I4 at a. point at thecenter of the throttle valve stem, which is formed with a little venturi 4|. The low speed adjustment screw is shown at 45.

In the modification shown in Figure 7, the auxiliary air valve has an annular lower end adapted to engage a seat 48, which is in the form of a spider, to limit the closing movement connected a tube 50 leading from the passage-' way 25. The valve 46 is also provided with upwardly and outwardly inclined passageways 5|,

I throughwhich the fuel is drawn when the throttle is open.

In the operation of the invention, when the engine is running under a normal load with the throttle, say, half way open, the auxiliary air valve 3| or 46 will be held open by the vacuum developed in the intake. But if the throttle is suddenly opened wider, relieving the vacuum, the auxiliary air valve will tend to close, thereby enriching the mixture, until the engine picks up speed.

With the throttle wide open, even with the engine running at high speed, if the operation of the auxiliary air valve were dependent entirely on vacuum, there would be a tendency for it to close and make too rich 2. mixture. With the present construction, however, the velocity of the air passing through the venturi 22 will hold the valve open, thereby supplying a comparatively lean mixture, but whenever the engine slows down under a heavy load, the valve will tend to drop automatically, decreasing the space between the same and the venturi and enriching the mixture, as is desirable under such conditions.

I have also found, however, that if the auxiliary air valve is subjected to the action of suction from the intake, with the engine idling or should be in its lower position when the engine is running at low speed or idling and, to make this possible, I have arranged the groove 31 so that it will be closed, thus shutting oif the vacuum from the auxiliary air valve whenever the throttle is closed, or open less than one eighth of its capacity. Then, when the engine is accelerated, the valve is initially in its lower position and will rise as the speed of the engine or the degree of vacuum increases.

From the above description, it will be seen that the auxiliary air valve is controlled automatically, partly'by suction from the intake and partly by the velocity of the air passing through the venturi 22, but that the suction is cut ofi whenever the throttle is closed, or open less than one eighth of its capacity.

The invention may be applied to any type of carburetor and while I have shown and described in detail the preferred embodiment thereof, it is apparent that the same may be considerably modified without departing materially from the scope of the appended claims.

I claim:

1. The combination with an intake passageway having a fuel inlet, an air inlet formed with a venturi, and a throttle valve for said passageway, of a valve for said air inlet within the venturi, a passageway from the intake to the air inlet valve and tending to open the latter by suction from the intake, and means connected with the throttle valve for cutting ofi the suction from said air inlet valve whenever the throttle is not open beyond a predetermined position.

2. The combination with an intake passageway having a fuel inlet, an air inlet, and a throttle valve for said passageway, of a valve for said air inlet, a passageway from the intake through the throttle valve stem to the air inlet valve and tending to open the latter by suction from the intake, said throttle valve stem being adapted to cut oil? the suction from said air inlet valve whenever the throttle is not open beyond a predetermined position.

3. 1 The combination with an intake passageway having a fuel inlet, an air inlet formed with a venturi, and a throttle valve for said passageway, of a valve for said air inlet within the venturi, a passageway from the intake through the throttle valve stem to the air inlet valve and tending to open the latter by suction from the intake, said throttle valve stem being adapted to cut off the suction from said air inlet valve whenever the throttle is not open beyond a prehaving an inlet formed with a'venturi, a fuel.

inlet into the venturi, and a throttle valve for said passageway, of an air inlet valve within the venturi, a passageway from the intake to the air inlet valve and tending to open the latter by suction from the intake, and means connected with the throttle valve for cutting OK the suction from said air inlet valve whenever the throttle is not open beyond a predetermined position.

5. The combinationwith an intake passageway having an inlet formed with a venturi, a fuel inlet into the venturi, and a throttle valve for said passageway, of an air inlet valve within the venturi, a passageway from the intake through the throttle valve stem to the air inlet valve and tending to open the letter by suction from the intake, said throttle valve stem being adapted to cut off the suction from said air. inlet valve whenever the throttle is not open beyond a predetermined position.

6. In combination, an intake passageway having an inlet, a throttle valve within said passageway, an air valve supported between said inlet and the throttle valve, communicating means from said air valve through the axis of the throttle valve to a point in the intake passageway beyond the throttle valve and operable by a presageway to open said air valve, and means connected with the throttle valve for cutting off the suction from said air valve whenever the throttle valve is not open beyond a predetermined position.

'7. In combination, an intake passageway having an inlet formed with a venturi, fuel inlets into the venturi, a throttle valve on the engine side of the venturi, an air valve within the venturi, a spring tending to close the air valve, an abutment preventing complete closure thereof. a passageway through which a predetermined degree of vacuum on the engine side of the throttle valve is operable to open the air valve away from said abutment without varying the size of the fuel inlets, and means connected with the throttle valve for cutting off the suction from said air valve whenever the throttle valve is not open beyond a predetermined position.

8. In combination, a fuel mixing chamber having an air inlet'and fuel inlets, a throttle valve on the engine side of said'chamber, an air valve within said chamber on the engine side of said tuel inlets in proximity thereto and adapted to move toward said fuel inlets when closing, a spring resisting the opening oi said air valve, and means for communicating the vacuum of the engine intake to the engine side of said air valve, whereby the air valve is opened by the combined influence oi the intake vacuum and the velocity oi the inflowing air stream past the fuel inlets.

9. In combination, a fuel mixing-chamber having an air inlet in the form of a venturi and having iuel inlets between the engine and the narrowest part or the venturi, an air valve within the venturi and opening toward the engine and away from the fuel inlets. a throttle valve on the engine side of the mixing chamber, a spring tending to move the air valve into the venturi to close the same, the suction from the engine side oi the throttle valve acting directly on the air valve to oppose the action oi the spring. whereby the air valve is opened partly by engine suction and partly by the velocity of the air stream past the fuel inlets.

. MARION MALLORY.

CERTIFICATE or CORRECTION.

Patent No. 2, 001, 337.

MARION MALLORY.

quiring 10,- should also appear It is hereby certified that error appears in the above numbered patent re correction as follows: In the drawings, Figs. 1 and 3, sheets 1 and 2, should appear 7 as shown below instead of as shown in the patent ig.

; and the F as part of the Letters Patent;

a /////1 4. is .s

and that the said Letters Patent should be read with these corrections therei that the same may conform to the record of the case in the Patent Office.

Signed and sealed this l5th day of October, A. D. 1935.

Leslie Frazer Acting Commissioner of Patents.

(Seal) 

